Tired of crummy gas and leaking needle & seats
Rubber o-rings? Here is table for methane (methanol not listed but probably same) . Same as gas except last one, 1 is best 4 is not recommended :
Perfluoro-
elastomer 1
Viton
Extreme 1
Aflas
TFE/P 2
Viton
FKM 1
EPDM
P.C. 4
Buna-N
NBR 1
Silicone 4
Fluoro-
silicone 2